The information I have is that Coldrick is from the Irish name McGoldrick, as stated on the above website, but I think that source confuses two Irish surnames, O Goilin and MagUalghairg/MacUalghairg. The fact that Golden and Goulding are used as substitute names for both surnames is the probable source of confusion. MacGoldrick, however, is always MagUalghairg in Irish, and it's likely that Coldrick is also. The claim that the MacGoldricks are a branch of the more famous O'Rourkes is not disputed by historians. The O Goilins were of a different origin.